Draft appliance for locomotive-boilers.



PATENTED DEC. 29, 1903.

W. B. WARREN. DRAFT APPLIANCE FOR LOCOMOTIVE BOILERS.

APPLIOATION FILED AUG. 29, 1903.

N0 MODEL.

Patented December 29, 1903.

PATENT ()EFIcE.

WILLIAM B. WARREN, OF ST. LOUIS, MISSOURI.

DRAFT APPLIANCE FOR LOCOMOTlVE-BOILERS.

SPECIFICATION forming part of Letters Patent No. 748,325,'dated December 29, 1903.

Application filed August 29, 1903. Serial No. 171.237. (No model.)

.To all whom it may concern/.-

Be it known that I, WILLIAM B. WARREN, a citizen of the United States, residing in the city of St. Louis and State of Missouri, have invented certain new and useful Improvements in Draft Appliances for Locomotive- Boilers, of which the following is a full, clear, and exact description, reference being had to the accompanying drawings, forming part'of this specification.

The invention relates to an improvement on the draft appliance shown and described in Letters Patent issued to me May 16, 1899, No. 625,225.

The present invention has reference to a construction whereby hot air from the smokearch of the boiler is delivered into a mixingchamber to be combined with steam as distinguished from the construction shown in said patent in which fresh air from the ex terior of the boiler is communicated to said mixing-chamber.

By the use of hot air in my draft appliance I obtain greater efficiency in the appliance,

due to better draft being afiorded when steam has heated air mixed therewith instead of cold fresh air. l

The invention consists in features of novelty hereinafter fully described, and pointed out in the claims.

Figure I is a vertical longitudinal section taken through the head end of the locomotive-boiler with my improved draft appliance situated therein. Fig. II is a vertical crosssection taken on line II II, Fig. I, through the boiler with my draft appliance shown in front elevation. FigIII is a vertical section taken on line III III, Fig. I.

through which the exhaust-steam from said cylinders may be conveyed to the steam-box struction to those shown in my Letters Patent hereinbefore referred to. I

12 designates a hot-air-conducting pipe leading from the spark-arrester screen to the mixing-chamber 10, as seen most clearly in Fig. I. This hot-air-conducting pipe has communication with the smoke-arch 4 to receive' heated air therefrom which passes through the screen 3 and is conducted to the mixing-chamber 10. Exhaust-steam from the engine cylinders is conducted to the steam-box 6 and flowing through the passageways therein is delivered to the mixing-chamber 10, to mingle with the hot-air conveyed thereto from the conducting-pipe 12. Suetion within the mixing-chamber is thereby created and the hot air and gases rising to the smoke-arch 4 are forcibly drawn through the conducting-pipe 12 into the mixing-chamber, where they are combined with the steam, and the mixture is blown through the outlet 11 vertically across the smoke-arch and into the boiler smoke-stack to intensify the draft.

By providing for the use of hot air to be mixed with the steam in the draft appliance I avoid lowering of the temperature of the steam, such as would occur by the communicationof cool fresh air into the mixing-chamber by the draft appliance to mix with the steam, and therefore gain greater efiiciency of blast into the smoke-stack of the boiler.

I claim as my invention-- 1. In a draft appliance, the combination with the smoke-arch, and smoke-stack of a boiler, of a spark-arrester screen mounted in the upper part of the smoke-arch, a steambox mounted beneath the spark arrester screen, a mixing-chain ber extending from the steam-box to the smoke-arch to a point above the spark arrester screen and below the smoke-stack, and an air-conducting pipe leading downwardly from the spark-arresting screen to that part of the mixing-chamber 'smoke-stack and surrounding the steam-box [O surrounding thesteam-box.

at its other end, and an air-conductingpipe 2. In a draft appliance, the combination secured to the under side of the spark-arrestwith the smoke-arch and the smoke-stack of the boiler, of a spark-arrester screen mounted in the upper part of the smoke-arch, a steambox mounted beneath the spark arrester screen, a mixing-chamber secured near one end to the spark-arrester screen below the ingscreen and to the mixing-chamber at the end which surrounds the steam-box.

WILLIAM B. WARREN. In presence of- E. S. KNIGHT, BLANCHE HOGAN. 

